Ruby off Rails
by Stoyan Zhekov
Kyoto, 17-May-2008

自己紹介
● 名前： ストヤン ｼﾞｪｺﾌ
● ブルガリア人
● ３人男の子のパパ

内容
● Coupling and Cohesion
● ウェブアプリに必要なこと
● ORM - Sequel (簡単な見解)
● Ruby ウェブエボリューション
● Enter Rack - The Middle Man
● Thin, Ramaze, Tamanegi
● まとめ, その他, 質問
08/05/19 3

Coupling and Cohesion (1)
● Cohesion - 凝集度 (ぎょうしゅうど)
http://en.wikipedia.org/wiki/Cohesion_(computer_science)
● Coupling - 結合度 (けつごうど)
http://en.wikipedia.org/wiki/Coupling_(computer_science)
08/05/19 4

Coupling and Cohesion (2)
正しいウェブアプリの組み立て方
● High cohesion
– 少ない動作でたかい機能性
● Low (loosely) coupling
– 簡単な入れ替え
08/05/19 5

Coupling and Cohesion (3)
Google vs Amazon
08/05/19 6

Coupling and Cohesion (5)
VS
08/05/19 7

Railsについて
08/05/19 8

Ruby on Rails
● 全部セットでよかった。しかし、今は？
● Convention over configuration – いいのか?
● DRY – 可能?
– Generators
– Plugins
– Libraries
08/05/19 9

Railsなしの人生
できる?
08/05/19 10

ウェブアプリに必要なこと
● データベースの使い方: ORM
● Request手順: CGI env, アップロード
● ルーティング: URLとクラスの組み合わせ
● Rendering (views): rendering libraries
● Sessions: persist objects or data
08/05/19 11

Database ORM
● Active Record ?= ActiveRecord
● ActiveRecord – たくさんの問題点
– http://datamapper.org/why.html
● Data Mapper – 早いけどまだ未完
– まだコンポジットキーなし
– 自分のDBドライバーが必要
● Sequel – よし。気に入ってる。
08/05/19 12

ORM – Sequel (なぜ?)
● Pure Ruby
● Thread safe
● Connection pooling
● DB queries構築のためのDSL
● ObjectとDBレコードの組み合わせの軽いORM
● Transactions with rollback
08/05/19 13

ORM – Sequel (Core)
● データベースのつなげ方
require 'sequel'
DB = Sequel.open 'sqlite:///blog.db'
DB = Sequel.open 'postgres://cico:12345@localhost:5432/mydb'
DB = Sequel.open(\"postgres://postgres:postgres@localhost/my_db\",
:max_connections => 10, :logger => Logger.new('log/db.log'))
08/05/19 14

ORM – Sequel (Core, 2)
DB << \"CREATE TABLE users (name VARCHAR(255) NOT NULL)\"
DB.fetch(\"SELECT name FROM users\") do |row|
p r[:name]
end
dataset = DB[:managers].where(:salary => 50..100).order(:name, :department)
paginated = dataset.paginate(1, 10) # first page, 10 rows per page
paginated.page_count #=> number of pages in dataset
paginated.current_page #=> 1
08/05/19 15

ORM – Sequel (Model)
class Post < Sequel::Model(:my_posts)
set_primary_key [:category, :title]
belongs_to :author
has_many :comments
has_and_belongs_to_many :tags
after_create do
set(:created_at => Time.now)
end
end
08/05/19 16

ORM – Sequel (Model, 2)
class Person < Sequel::Model
has_many :posts, :eager=>[:tags]
set_schema do
primary_key :id
text :name
text :email
foreign_key :team_id, :table => :teams
end
end
08/05/19 17

Evolution
08/05/19 18

Ruby Web Evolution
Webrick Mongrel Event Thin Ebb
Machine
08/05/19 19

Thin ウェブサーバー
● 早い – Ragel and Event Machine
● クラスタリング
● Unix sockets - nginx
● Rack-based – Rails, Ramaze etc.
● Rackup ファイルサポート (後で)
08/05/19 20

Thin + Nginx
thin start --servers 3 --socket /tmp/thin
thin start --servers 3 --port 3000
# nginx.conf
upstream backend {
fair;
server unix:/tmp/thin.0.sock;
server unix:/tmp/thin.1.sock;
server unix:/tmp/thin.2.sock;
}
08/05/19 21

問題点
Merb Ramaze Sinatra ...
How to connect them?
CGI Webrick Mongrel Thin
08/05/19 22

ソリューション - Rack
Merb Ramaze Sinatra ...
Rack – The Middle Man
CGI Webrick Mongrel Thin
08/05/19 23

Rackって何?
08/05/19 24

Rackって何なの?
http://rack.rubyforge.org/
By Christian Neukirchen
08/05/19 25

Rackって何？
● HTTPっぽいもののRuby APIのための簡単な仕様
(とその実装)
– Request -> Response
● callメソッドを持ち、envを受け取り以下を返すよう
なオブジェクト:
– a status, i.e. 200
– the headers, i.e. {‘Content-Type’ => ‘text/html’}
– an object that responds to each: ‘some string’
08/05/19 26

これがRackだ!
class RackApp
def call(env)
[ 200, {\"Content-Type\" => \"text/plain\"}, \"Hi!\"]
end
end
app = RackApp.new
08/05/19 27

Free Hugs
http://www.freehugscampaign.org/
08/05/19 28

Hugs ウェブアプリ (1)
p 'Hug!'
08/05/19 29

ruby hugs.rb
%w(rubygems rack).each { |dep| require dep }
class HugsApp
def call(env)
[ 200, {\"Content-Type\" => \"text/plain\"}, \"Hug!\"]
end
end
Rack::Handler::Mongrel.run(HugsApp.new, :Port => 3000)
08/05/19 30

Rack::Builder
require 'hugs'
app = Rack::Builder.new {
use Rack::Static, :urls => [\"/css\", \"/images\"], :root => \"public\"
use Rack::CommonLogger
use Rack::ShowExceptions
map \"/\" do
run lambda { [200, {\"Content-Type\" => \"text/plain\"}, [\"Hi!\"]] }
end
map \"/hug\" do
run HugsApp.new
end
}
Rack::Handler::Thin.run app, :Port => 3000
08/05/19 31

Rack Building Blocks
● request = Rack::Request.new(env)
– request.get?
● response = Rack::Response.new('Hi!')
– response.set_cookie('sess-id', 'abcde')
● Rack::URLMap
● Rack::Session
● Rack::Auth::Basic
● Rack::File
08/05/19 32

Rack Middleware
自分のuse Rack::「...」 ブロックを作れる?
class RackMiddlewareExample
def initialize app
@app = app
end
def call env
@app.call(env)
end
end
08/05/19 33

ウェブアプリに必要なこと
● データベースの使い方(ORM): Sequel
● Request手順: Rack::Request(env)
● ルーティング: Rack 'map' and 'run'
● Rendering/views: Tenjin, Amrita2
● Sessions: Rack::Session
08/05/19 34

Does it scale?
08/05/19 35

rackup hugs.ru
require 'hugs'
app = Rack::Builder.new {
use Rack::Static, :urls => [\"/css\", \"/images\"], :root => \"public\"
map \"/\" do
run lambda { [200, {\"Content-Type\" => \"text/plain\"}, [\"Hi!\"]] }
end
map \"/hug\" do
run HugsApp.new
end
}
Rack::Handler::Thin.run app, :Port => 3000
08/05/19 36

Hugs サービス
● rackup -s webrick -p 3000 hugs.ru
● thin start --servers 3 -p 3000 -R hugs.ru
● SCGI
● FastCGI
● Litespeed
● ....
08/05/19 37

Rack-based フレームワークス
● Invisible – thin-based フレームワーク in 35 LOC
– http://github.com/macournoyer/invisible/
● Coset – REST on Rack
● Halcyon – JSON Server Framework
● Merb
● Sinatra
● Ramaze
● Rails !?
08/05/19 38

RailsにもRackが必要
● RailsはRackをすでに持っている、しかし:
– raw req -> rack env -> Rack::Request ->CGIWrapper ->
CgiRequest
● Ezra Zygmuntowicz (merb)'s repo on github
– http://github.com/ezmobius/rails
– raw req -> rack env -> ActionController::RackRequest
– ./script/rackup -s thin -c 5 -e production
08/05/19 39

Ramaze
● 何？: モジュラーウェブアプリ フレームワーク
● どこで？: http://ramaze.net/
● どうやって？: gem install ramaze
● git clone http://github.com/manveru/ramaze.git
● 誰が？: Michael Fellinger and Co.
08/05/19 40

なぜ Ramaze?
● モジュラー (low [loosely] coupling)
● Rack-based
● 簡単な使い方
● たくさんの例 (~25) – facebook, rapaste
● フリースタイルな開発
● フレンドリーなコミュ - #ramaze
● “All bugs are fixed within 48 hours of reporting.”
08/05/19 41

Deployment オプションズ
● CGI ● Ebb
● FastCGI ● Evented Mongrel
● LiteSpeed ● Swiftiplied Mongrel
● Mongrel ● Thin
● SCGI ● Rack-basedなら使える
● Webrick
08/05/19 42

Templating engines
● Amrita2 ● RedCloth
● Builder ● Remarkably
● Erubis ● Sass
● Ezamar ● Tagz
● Haml ● Tenjin
● Liquid ● XSLT
● Markaby
08/05/19 43

Ezamar
08/05/19 44

本当に簡単?
%w(rubygems ramaze).each {|dep| require dep}
class MainController < Ramaze::Controller
def index; \"Hi\" end
end
class HugsController < Ramaze::Controller
map '/hug'
def index; \"Hug!\" end
end
Ramaze.start :adapter => :thin, :port => 3000
08/05/19 45

Ramaze使い方
class SmileyController < Ramaze::Controller
map '/smile'
helper :smiley
def index
smiley(':)')
end
end
08/05/19 46

Ramaze 使い方 (2)
module Ramaze
module Helper
module SmileyHelper
FACES = {
':)' => '/images/smile.png',
';)' => '/images/twink.png'}
REGEXP = Regexp.union(*FACES.keys)
def smiley(string)
string.gsub(REGEXP) { FACES[$1] }
end
end
end
end
08/05/19 47

他のStack
● ORM – Sequel
● ウェブサーバー – Thin + NginX
● Rack Middleware
● Ramaze フレームワーク
● Templates – HAML, Tenjin, Amrita2
08/05/19 48

まとめ
● Railsを使うなとは言いません
● オープンマインドで
● SequelはORMに適している
● Rackを使え! – DIY framework, DIY server
● Ramazeはかっこよくて、使いやすい!
08/05/19 49